Aleuritic Acid — Uses in Fragrance & Specialty Chemistry

Most shellac is sold as a coating resin. A smaller, specialist trade takes it apart chemically. The main product of that trade is aleuritic acid, a building block for fine-fragrance musks and specialty chemistry. Here is what it is, how it is made, and where it goes.

What aleuritic acid is

Aleuritic acid is 9,10,16-trihydroxypalmitic acid (also written 9,10,16-trihydroxyhexadecanoic acid): a 16-carbon fatty acid with three hydroxyl groups. Its CAS number is 533-87-9 and its formula C16H32O5 (full identity and specification on our aleuritic acid product page). It is the main acid building block of shellac, making up roughly a third of the resin, and it is supplied as an off-white to cream powder or flakes.

Chemical name	9,10,16-Trihydroxypalmitic acid
CAS number	533-87-9
Formula	C16H32O5 (molecular weight about 304)
Source	Shellac, by alkaline hydrolysis
Form	Off-white to cream powder or flakes
Grades	Technical and refined; assay stated on the batch COA

How it is made from shellac

1. Saponification. Shellac is treated with an alkali, which breaks the ester bonds of the resin and frees its acids.
2. Separation. Aleuritic acid is separated from the other acids of the resin, typically as its salt.
3. Acidification and purification. The salt is converted back to the free acid and purified, for example by recrystallisation, to the technical or refined grade.

The quality of the starting shellac and the purification route decide the assay and colour of the product, which is why buyers ask for a sample from the same process before the first bulk order.

Uses in fragrance

Aleuritic acid's main commercial use is as a natural starting material for macrocyclic musks, large-ring molecules prized in fine fragrance for their soft, long-lasting musky note. Classic targets made from it include:

• Ambrettolide and isoambrettolide, macrocyclic lactone musks.
• Civetone, a macrocyclic ketone musk.

Its chain length and the position of its hydroxyl groups make it a convenient precursor for these rings. Much of the demand comes from fragrance-chemical manufacturers, many of them in China; see our China market guide.

Uses in specialty chemistry

• Organic synthesis: a bio-based trihydroxy C16 building block for esters, lactones and custom molecules.
• Polymer research: studied as a monomer for bio-based polyesters and coatings.
• Pharmaceutical chemistry: as an intermediate in research and custom synthesis.

What to put on the purchase order

• Grade (technical or refined) and the minimum assay, with the test method.
• Acid value, hydroxyl value, loss on drying and melting range on the batch COA.
• SDS, TDS and certificate of origin; lined fibre drums or HDPE-lined bags.
• A sample from the same process family before the first bulk shipment.

Because aleuritic acid is made from shellac, sourcing close to India's lac belt shortens the chain from raw lac to finished acid. Full specifications are on our aleuritic acid supplier page (CAS 533-87-9).

Quick answers

What is aleuritic acid? Aleuritic acid is 9,10,16-trihydroxypalmitic acid (CAS 533-87-9), the main acid building block of shellac, obtained by alkaline hydrolysis of the resin.

What is aleuritic acid used for? Mainly as a natural starting material for macrocyclic musk fragrances such as ambrettolide, isoambrettolide and civetone, and as a building block in specialty synthesis and polymer research.

How is aleuritic acid made? By saponification (alkaline hydrolysis) of shellac, separation of the aleuritic acid, usually as a salt, then acidification and purification.

How much aleuritic acid is in shellac? Roughly a third of the resin, which is why shellac is the commercial source.

What grades of aleuritic acid are sold? Technical and refined grades. The batch COA states the assay, acid value and hydroxyl value.

This guide summarises industry practice as of October 2026. Confirm current regulations and requirements for your market before ordering. It is not legal advice.